The present invention relates to an apparatus for cleaning a photoconductive element and an apparatus for collecting residual toner both installed in an electrophotographic copying machine or the like.
In electrophotographic copying machines or the like using a photoconductive element, particularly one in the form of a belt, a cleaning apparatus is installed to clear a photoconductive element of toner particles remaining thereon after the transfer of a toner image onto a sheet. A known type of cleaning apparatus includes a cleaning member constituted by a roller on which bristles are set and which has magnets thereinside. A counter member is formed of a soft material and located at the back of a belt in facing relation with the cleaning member. A photoconductive element is held between the cleaning member and the counter member while the cleaning member is kept in pressing contact with the photoconductive element. In this type of prior art cleaning apparatus, the cleaning member is required to clean the photoconductive element in even and soft contact with the surface of the latter. To set up an even pressure distribution between the cleaning member and the belt, that surface of the counter member which engages with the back of the belt needs be processed to a high precision. Poor flatness of the mentioned surface of the counter member would make the pressure distribution irregular; in a lower pressure area, cleaning would be incomplete while, in a higher pressure area, either surface of the belt would be worn out or shaved off to deteriorate the strength of the belt or even the recording characteristics thereof. Usually, the base of a belt is formed of an organic material such as a polyester film or an inorganic material such as a stainless steel sheet. During repeated movements of the belt, the base of the material is progressively shaved off and the resulting particles are deposited on the belt. Thease particles are entrained by the belt to adhere to the surface of a drive roller which is engaged with the belt, reducing the friction between the belt and the drive roller. Furthermore, the particles shaved off the belt are deposited on the counter member to disturb the even contact of the belt surface with the cleaning member. Shaving of the base of the belt per ce causes such uneven contact between the cleaning member and the belt as well as a decrease in the drive transmission force from the drive roller. A solution heretofore proposed to this problem is the provision of an additional cleaning member which is engaged with the back of the belt. This, however, results in the intricacy of construction and increase in cost.
In the meantime, the residual toner removed from the belt surface by the cleaning apparatus is discharged from the cleaning apparatus by toner discharging means which comprises a toner discharge casing, a screw disposed inside the casing, etc. The residual toner is then collected in a container to be wasted. When filled up with the toner, the container is taken out from the machine and discarded. Vibration entailed by the removal of the container tends to allow the toner particles to drop from the vicinity of a toner outlet of the casing and/or from the toner outlet itself where they may form light bridges. Then, the toner would contaminate various parts located below the casing or even affect their functions.
After the filled container has been unloaded from the machine, a new empty container has to be loaded. Should one forget to load an empty container, the toner discharged from the toner outlet during operation of the machine would drop onto the parts located below to invite the same results as the above-stated.
Furthermore, when the orientation of the container inside the machine is incomplete or inverted, the toner discharged from the toner outlet will partly miss the container to contaminate the interior of the machine due to the asymmetrical shape of the container. Though such an accident may be avoided if a stop or the like is used to prevent the container from being oriented inproperly, this adds to the number of structural elements and, therefore, the production cost.